This invention relates to an elastomeric mounting and in particular, though not exclusively, to an elastomeric mounting adapted to accommodate a high degree of deflection in a direction of normal compression loading.
It relates also, though not exclusively, to an elastomeric mounting which preferably allows relatively unrestricted movement in at least one direction in a plane perpendicular to the direction of normal compression loading.
The invention has as one object the provision of an elastomeric mounting which has an improved compression deflection capability and which potentially is of lower cost than established designs of mountings. Preferably the elastomeric mounting is effective also to dampen the transmission of acoustic frequency vibrations.
According to one aspect of the invention an elastomeric mounting module comprises two rigid end members, each end member being substantially of L-shape in cross-section and oriented with two inwardly facing surfaces of the L-shape generally facing towards inwardly facing surfaces of the other end member, and an element of elastomeric material extending between and bonded to said inwardly facing surfaces, respective bonded surfaces of said end members being offset at least in part as considered in the direction of normal compression loading and in a traverse direction perpendicular to said loading direction.
It is envisaged that preferably the two inwardly facing, bonded surfaces of an end member will lie relative to one another at an angle in the range 80xc2x0 to 115xc2x0, more preferably in the range 85xc2x0 to 100xc2x0. The bonded surfaces of each end member may lie in planes substantially perpendicular relative to one another.
The two end members may be identical, so helping to minimise production costs.
Preferably the respective bonded surfaces are partly overlapped as viewed along said direction of normal compression loading. Viewed in a first transverse direction perpendicular to the compression loading direction said bonded surfaces preferably are spaced apart, at least in the absence of compression loading. Viewed in a second transverse direction perpendicular to said first transverse direction the elastomeric element preferably is substantially free from direct compression loading at least at normal operating loads.
The relative shapes of the module parts and their sizes preferably are selected so that during initial loading in said direction of compression the elastomeric element is loaded in shear and compression, in combination.
The elastomeric element preferably is bereft of any internal reinforcement or interleaves. Preferably in at least one transverse direction it is free from either internal or external structure that might inhibit its freedom to bulge, at least until any buffer action occurs under extreme or shock load conditions.
Preferably, but not necessarily, the elastomeric element is of a substantially solid shape. Preferably it is bereft of cavities, and more preferably it is bereft of any openings extending therethrough in a direction perpendicular to the cross-sectional plane of said L shape.
Preferably the elastomeric material extends wholly into the corner space region between the two inwardly facing surfaces of an end member. It is believed that this usefully assists in deadening the transmission of sound through the mounting.
Unbonded end surfaces of the rigid members may be provided with location means, such as tapped holes, to allow rigid members of one module to be located relative to corresponding rigid members of a second module.
Tie bars may be provided to secure one pair of end members in proximity to one another, e.g. in direct back-to-back contact, and another to secure the other pair at a prescribed spacing.
The invention provides also an elastomeric mounting assembly which is comprised by two or more elastomeric mounting modules secured in position relative to one another. The assembly may be secured to supported or supporting structure which is utilised to maintain rigid members of the modules in a predetermined spatial relationship.
The assembly may comprise modules having elastomeric elements of different sizes and/or of different volumes. Preferably none of the elastomeric elements of the assembly have a volume greater than 15 litres.
Preferably the same cross-sectional size and shape of rigid end member is used in two or more modules of different sizes or which have elastomeric elements of different volumes.